Systems that identify and track objects within a particular area include security systems used to identify unauthorized access to restricted areas and set off alarms when someone enters an unauthorized area. Conventional security systems control entry access to an enclosed structure. Typically, the enclosed structures have secured doors and windows that prevent anyone without a key from entering the building. Many commercially available systems require anyone entering an enclosure to confirm their access authorization by first entering a code at a keypad at the entrance to the enclosure, or swipe a card or similar device past an access reader near the entry point. The security confirms the identity of the person based on the access code or encoded information on the card and unlocks the door for entry.
These systems require access authorization at each point of entry. In addition, these systems do not have an economic way of monitoring people as they move within or leave an enclosure. As a result, it is possible for people to remain in a building intentionally or accidentally without detection. In emergency situations it can be critical to know if everyone has been evacuated to know when to initiate search and rescue procedures. Also, individuals may need to enter a building late at night or on holidays to complete a work assignment. If they become ill or injured, this problem goes undetected since systems such as those described in the above examples cannot detect when someone leaves a building or if they remain in the building.
Additionally, if someone is in an enclosure, the only methods to control access from one area of an enclosure to another area are to install doors with access authorization hardware, to install video security cameras to monitor movement, or to employ security guards at checkpoints to control access. Any of these solutions is complex and costly.
Access control systems also limit flexibility to readily change the configuration of the work space or use a common space for workers with different levels of authorization. For example, manufacturers who have several contract manufacturers may use the same space for manufacturing different processes. Since the contract groups operating in this space are employees of different companies, it is desirable for these workers to have access only to the floor space reserved for their activities. It is also, desirable not to build enclosures and install security systems to control access since the manufacturing needs of the company and the space required for these changes may change quickly over time depending on business opportunities or economic conditions.
Other conventional tracking systems include package tracking and warehousing. Tracking of packages includes affixing bar codes to letters and packages and scanning the labels at pickup and delivery points. The identity of the letter or package retrieved from the barcode label might be combined with positional information based on global positioning or more simply based on a known route or reported location of the delivery person. In each case a delivery person must scan the barcode attached to the letter or package. Also, the spatial location, presence or identity of the package within a delivery vehicle or warehouse is not known continuously in real time because bar code readers used to establish identity and location required close proximity of the bar code reader to the bar code.
In warehousing, which involves assigning items numbers to inventory, if someone fails to place an item in the correct location in the warehouse the item may be lost. Warehousing does not provide security features to insure that items really enter and leave the warehouse when management thinks they are entering or leaving the warehouse, and efficient use of the warehouse depends on accurate prediction of the space requirement for an inventory supply and requires reorganizing the warehouse space in case inventory levels of particular items change in response to business conditions.